<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>实验六</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            text-align: center;
        }

        .div1 {
            background-color: yellow;
            width: 20%;
            height: 200px
        }

        .div2 {
            background-color: purple;
            width: 20%;
            height: 200px
        }

        .div3 {
            background-color: red;
            width: 20%;
            height: 200px
        }

        .div4 {
            background-color: blue;
        }

    </style>
</head>
<body>
<div class="div1">DIV1</div>
<div class="div2">DIV2</div>
<div class="div3">DIV3</div>
<div class="div4">DIV4</div>
</body>
</html>